Production of polyester yarn

ABSTRACT

in which R1 and R2 are the same or different lower alkylene units such as ethylene, propylene and so forth up to 5 carbon atoms, R is an alkyl group containing 5 to 17 carbon atoms, and n has a value to produce a molecular weight of at least about 300. Preferably, the yarn is thereafter heated for 10 to 160 seconds at a temperature of from about 215* to 230*C. The yarn is particularly useful in the production of tire cord.   An improved polyester yarn is prepared by applying to the yarn a finish composition consisting essentially of a polyalkylene glycol compound having the formula

Dec. 9, 1975 1 PRODUCTION OF POLYESTER YARN [75] Inventors: Robert Moore Marshall, Chester;

Kimon Constantine Dardoufas, Richmond, both of Va.

[73] Assignee: Allied Chemical Corporation, New

York, N.Y.

[22] Filed: Apr. 1, 1974 [21] Appl. No: 456,502

[52] US. Cl. 428/395; 57/140, 57/153 [51] Int. Cl. D026 3/36; 002M 13/20 [58] Field of Search 117/138.8 F, 139.5 CQ,

[56] References Cited UN1TED STATES PATENTS 2,481,278 9/1949 Ballard et a1 260/615 2,626,887 1/1953 Amelang r. 154/136 2,810,694 10/1957 McLean et a1 4 252/8.S 3,338,830 8/]967 Stokes et al. r. 252/89 3,446,734 5/1969 Coats 252/83 3,513,184 6/1970 Potter .4 Z52/8.75 3,672,977 6/1972 Dardoufas 117/1388 F 3,686,!20 8/1972 Creely 252/8.8 3,834,935 9/1974 Symm et a1. 117/138.8 B

FORElGN PATENTS OR APPL1CATIONS 588,021 12/1959 Canada OTHER PUBLICATIONS Finch, Def. Pub. of Ser. No. 791,501, filed 1-1969, published on Sept. 29, 1970, Def. Pub. No. T878,0l2.

Primary ExaminerP. E. Willis, Jr. Attorney, Agent, or Firm Fred L. Kelly ABSTRA T An improved polyester yarn is prepared by applying to the yarn a finish composition consisting essentially of a polyalkylene glycol compound having the formula in which R and R are the same or different lower alkylene units such as ethylene, propylene and so forth up to 5 carbon atoms, R is an alkyl group containing 5 to 17 carbon atoms, and n has a value to produce a molecular weight of at least about 300. Preferably, the yarn is thereafter heated for 10 to I60 seconds at a temperature of from about 215 to 230C. The yarn is particularly useful in the production of tire cord.

4 Claims, No Drawings PRODUCTION OF POLYESTER YARN BACKGROUND OF THE INVENTION This invention relates to multifilament polyester yarns and particularly to improved multifilament polyester yarns for industrial uses. More particularly, it relates to an improved multifilament polyester yarn and a new fiber finishing process for polyester yarns in which novel fiber finish compositions are applied to said yarns. Still more particularly, it relates to a fiber finish composition designed for tire cord processing for polyester yarns.

Many fiber finish compositions are known. Some are quite specific in composition and relate to specific type fibers. Small changes in fiber finish composition frequently result in tremendous improvements in not only processing but also in end use of the fiber.

Polyester tire yarn finishes generally consist of a combination of a lubricant, an antistat, and several emulsifiers. For example, US. Pat. No. 3,687,721 discloses an improved polyester tire yarn treated with a composition comprising decaglycerol tetraoleate, glycerol monooleate, ethoxylated tall oil fatty acid, sulfated glycerol trioleate, ethoxylated alkylamine and hexadecyl stearate. Obviously, maintaining the proper ratio of lubricant, antistat and emulsifiers is essential for consistent performance of the tire yarn. Moreover, many prior art processes require applying a first finish composition during spinning of the yarn and a subsequent overfinish in order to obtain optimum physical properties. Clearly, it would be a significant advance in this art to find a single ingredient finish that could be used as a single finish for polyester yarn or as an overfinish to provide a tire yarn with excellent properties for use in tires.

SUMMARY OF THE INVENTION Therefore, it is a primary object of this invention to provide an improved polyester multifilament yarn which is treated with a single component finish composition. It is another object of this invention to provide a method of finishing polyester tire yarn which results in an improved compression-extension durability of the fiber in rubber.

These and other objects are accomplished in accordance with this invention with a finish for polyester yarns consisting essentially of a polyalkylene glycol compound having the formula in which R and R are the same or different alkylene units having up to 5 carbon atoms, R is an alkyl group containing 5 to 17 carbon atoms and n has a value to produce a molecular weight of at least about 300. The finish composition may be diluted with water to a water content up to about 80 weight percent of the diluted composition. The finish composition is applied to polyester yarns including, for example, polyethylene terephthalate yarns be any known means including bath, spray, padding, kiss roll application or the like. The composition is applied to the yarn in an amount sufficient to supply 0.5 to 1.5% polyglycol ester based on the weight of the yarn. The yarn is made into tire cord by known procedures and thereafter tensilized by heat- 2 ing for to 160 seconds at a temperature of from about 215 to 230C. to improve heat stability.

Certain terms referred to within the specification and claims are defined below. Disc fatigue" is defined and 5 described in scope, principle and testing procedure as follows:

This test is used to determine the ability of a textile tire cord to resist degradation when subjected to repeated cycles of compression and extension.

The disc fatigue tester cyclically compresses and extends cord specimens that have been embedded in rubber blocks. After a specified number of compression and extension cycles, the cords are removed from the blocks and tested for tensile strength. The strength of these cords is then compared with that of similar cords that have been cured in rubber but have not been fatigued. The results are then reported in present strength retained. This method is more specifically described in US. Pat. No. 2,595,069.

DESCRIPTION OF THE PREFERRED EMBODIMENT As mentioned above, the value of n in the formula is such as to yield a molecular weight of at least about 300. There is no known maximum limitation for the molecular weight although the lower range, particularly that of from 300 to 600, is preferred since compounds in this range are more soluble as well as being more available and economical. The critical nature of the minimum molecular weight of the polyalkylene glycol compound results from the fact that excessive fuming during drawing of the fiber and poor static protection results when the molecular weight is less than about 300.

The preferred polyalkylene glycol ester compounds of the present invention are copolymers made from ethylene oxide and propylene oxide. The ethylene oxide and propylene oxide may be reacted successively or simultaneously to form mixed polyalkylene glycol ester compounds. For example, with carboxylic acids such as stearic acid, mixed polyoxyethylated-polyoxypropylated monoesters result in accordance with the following equation:

n-i-on x CH,CHCH, y cinch,

3 tained with polyoxyethylated-polyoxypropylated monoesters which are condensation products of 50% ethylene oxide and 50% propylene oxide, said monoesters having a viscosity of 100-660 S.U.S., preferably 100 to 260 S.U.S.

In addition to the critical nature of the finish composition, it has also been found that the heat treatment of the yarn subsequent to the application of the process finish composition is likewise necessary for achieving optimum results in accordance with the invention. The use of too high a temperature of heat treatment will cause fusion of the fibers as well as causing a drop in strength properties. The maximum temperature will be governed by the melting point or degradation of the particular fibers used. The minimum temperature necessary to achieve satisfactory heat stability of the tire cord in this process has been found to be about 200C. when polyethylene terephthalate is the polyester fiber. The preferred temperature is from about 215C. to 230C.

Furthermore, the time/temperature relationship of the heat treatment must be controlled so that the fiber properties do not suffer impairment. Too long a treatment, even at preferred temperatures will tend to degrade the fibers. Normally, the heat treating step will be carried out so that the surface of the fibers will be raised rapidly to a temperature of 200C. to 230C, preferably 215C. to 230C. and kept at that temperature for several seconds, preferably to 160 seconds. A satisfactory criterion for determining the best time/- temperature relationship is to measure the heat stability of the fiber, both heat treated and untreated. Of course, the instant heat treatment should significantly improve the heat stability of the fiber. Any means for heating the surface of the fiber may be used and a large variety of suitable apparatus is available in the trade.

The yarns of this invention can be processed by any spin draw process or spinning and separately drawing process available to the art in the patent and technical literature, using any suitable polyester which provides high tenacity yarn of about 9 grams per denier and minimum elongation of about 13 percent. The preferred polyesters are the linear terephthalate polyesters, i.e., polyesters of a glycol containing from 2 to carbon atoms and a dicarboxylic acid component containing at least about 75% terephthalic acid. The remainder. if any, of the dicarboxylic acid component may be any suitable dicarboxylic acid such as sebacic acid, adipic acid, isophthalic acid, sulfonyl-4,4-dibenzoic acid, or 2,S-dibenzofurandicarboxylic acid. The glycols may contain more than two carbon atoms in the chain, e.g., diethylene glycol, butylene glycol, decamethylene glycol, and bis-1,4-(hydroxymethyl)cyclohexane. Examples of linear terephthalate polyesters which may be employed include poly (ethylene terephthalate), poly(- butylene terephthalate), poly(ethylene terephthalate/S-chloroisophthalate) (85/15), poly(ethylene terephthalate/S-[sodium sulfo] isophthalate) (97/3), poly( cyclohexane-l ,4-dimethylene terephthalate and poly(cyclohexanel ,4-dimethylene terephthalate/hexahydroterephthalate) (75/ In accordance with one preferred procedure polyethylene terephthalate yarn is first treated with from about 0.3 to about 0.6 weight percent based on the weight of the yarn of a spin finish" composition consisting essentially of about 10 to about 20 weight percent of said composition of each hexadecyl stearate and refined coconut oil, about 3.0 to about 6.0 weight percent of said composition of ethoxylated tallow amine, about 10 to about 20 weight percent of said composition of ethoxylated lauryl alcohol, about 8.0 to about 12.0 weight percent of said composition of sodium salt of alkylaryl sulfonate, about 1.0 to about 3.0 weight percent of dinonyl-sodium-sulfosuccinate, about 1.0 to about 3.0 weight percent of said composition of 4,4'-thio-bis-(3- methyl-6-tertbutylphenol), about 35 to 50 weight percent of said composition of white mineral oil having a boiling point of between 510F. and 620F. and a viscosity of between 38 to 40 S.U.S. at F. wherein at least about 0.15 to about 0.30 weight percent is retained on said yarn, and then the yarn is treated with the polyglycol ester overfinish of the present invention.

In order to demonstrate the invention, the following examples are given. They are provided for illustrative purposes only and are not to be construed as limiting the scope of the invention, which is defined by the appended claims. In these examples, parts and percentages are by weight, unless otherwise indicated.

EXAMPLE 1 For comparative testing, a polyethylene terephthalate yarn was prepared in accordance with one procedure described in US. Pat. No. 3,672,977, i.e., a 1300 denier, 192 filament yarn was prepared comprised of polyethylene terephthalate filaments treated with about 0.45 percent based on the weight of the yarn of a liquid spin finish consisting of 14.7 parts refined coconut oil, 14.7 parts hexadecyl stearate, 12.7 parts ethoxylated lauryl alcohol, 9.8 parts sodium petroleum sulfonate, 4.9 parts ethoxylated tallow amine, 2 parts of sodium salt of sulfonated succinic ester, 2 parts 4,4- thiobis(6-tert-butyl-m-cresol) and 39.2 parts mineral oil having a boiling point between 510F. and 620F. Drawing performance of the yarn was excellent. Finish oil on the fiber was 0.2 weight percent. For conve nience, this yarn is designated Yarn A.

In accordance with one embodiment of the present invention, a polyglycol ester described herein was applied as an overfinish to Yarn A. The polyglycol ester finish was a condensation product of 50% ethylene oxide and 50% propylene oxide terminated by reaction with lauric acid, having a viscosity of S.U.S. at 100F. The polyglycol ester was applied to samples of the yarn at 0.8% based on the weight of the yarn, resulting in a total oil on yarn of 1.0%, including the initial (spin) finish. This yarn sample was designated as Yarn B.

The two samples were twisted and plied into greige cord. The resulting cords were tensilized by a standard tensilization procedure and the tensilized cord was then tested in the above-described disc fatigue test where the percent breaking strength (8.8.) retention is recorded. The results are shown in Table 1.

These data represent an average of 12 replications per yarn sample.

EXAMPLE 2 This example shows that the polyglycol ester finish of the present invention may be used with excellent results as a single component finish. The polyglycol ester finish used was a condensation product of 50% ethyl ene oxide and 50% propylene oxide terminated with lauric acid, having a viscosity of I25 S.U.S. at 100F. This finish was applied as initial finish (spin finish) to polyethylene terephthalate tire yarn (approximately 7800 denier, 192 filaments) by means of a kiss roll during spinning. After drawing, the yarn was heated to 2l5-230C. for a few seconds. The finished yarn was readily twisted and plied into greige cord. The resulting cords were then tensilized and tested as in Example 1.

The finish was applied at four levels ranging from 0.20 to 1.0% based on the weight of the fiber. Yarns with finish levels of from 0.77 to 1.0% were considered most desirable in view of relatively low finish required and significantly improved compression-extension durability in rubber as tested in the above-described disc fatigue test where the present strength retention is. re corded. The results are shown in Table I].

6 These data represent an average of 12 replications per yarn sample.

We claim: 1. Polyester yarn having incorporated thereon a finish composition consisting essentially of a polyalkylene glycol condensation product having the formula:

where R is an alkyl group having 6 to 18 carbon atoms, x and y are the number of moles of propylene oxide and ethylene oxide respectively and wherein ethylene oxide comprises 40 to 60% of the combined total of ethylene oxide and propylene oxide and x+y has a value to produce a molecular weight of from 300 to 600, said poly alkylene glycol condensate being incorporated on the yarn at an application level of 0.50% to 1.5% based on the weight of the yarn.

2. The polyester yarn of claim 1 wherein the polyalkylene glycol compound has a viscosity of from to 660 S.U.S. at l00F.

3. The polyester yarn of claim 1 wherein the polyalkylene glycol compound has a viscosity of from 100 to 260 S.U.S. at 100F.

4. The polyester yarn of claim 1 wherein the polyalkylene glycol compound is a condensation product of ethylene oxide and propylene oxide terminated with lauric acid, having a viscosity of about S.U.S. at 100F. 

1. POLYESTER YARN HAVING INCORPORATED THEREON A FINISH COMPOSITION CONSISTING ESSENTIALLY OF A POLYALKYLENE GLYCOL CONDENSATION PRODUCT HAVING THE FORMULA:
 2. The polyester yarn of claim 1 wherein the polyalkylene glycol compound has a viscosity of from 100 to 660 S.U.S. at 100*F.
 3. The polyester yarn of claim 1 wherein the polyalkylene glycol compound has a viscosity of from 100 to 260 S.U.S. at 100*F.
 4. The polyester yarn of claim 1 wherein the polyalkylene glycol compound is a condensation product of ethylene oxide and propylene oxide terminated with lauric acid, having a viscosity of about 125 S.U.S. at 100*F. 